สอบถามข้อมูลการนำค่าจาก Serial port มาพล้อตกราฟในC# (เอาแคตัวเลขอย่างเดี่ยวไม่เอาสตริงครับ)

#include <SD.h>
#include <SPI.h>
#include "Wire.h"
int SHT_clockPin = 9;
int SHT_dataPin  = 8;
String inputstring = "";                                                       //a string to hold incoming data from the PC
String sensorstring = "";
boolean input_stringcomplete = false;                                          //have we received all the data from the PC
boolean sensor_stringcomplete = false;;
void setup(){
  Wire.begin();
  Serial.begin(9600);
  Serial2.begin(19200);
  inputstring.reserve(5);                                                   //set aside some bytes for receiving data from the PC
  sensorstring.reserve(30);
  
  
  setDateTime(); //MUST CONFIGURE IN FUNCTION
}

void loop(){
  
 // sht15();
  printDate();
  writeSD();
  delay(1000);
}
void serialEvent() {                                                         //if the hardware serial port_0 receives a char              
               char inchar = (char)Serial.read();                               //get the char we just received
               inputstring += inchar;                                           //add it to the inputString
               if(inchar == '\r') {input_stringcomplete = true;}                //if the incoming character is a <CR>, set the flag
              }  

void serialEvent3(){                                                         //if the hardware serial port_3 receives a char 
              char inchar = (char)Serial2.read();                              //get the char we just received
              sensorstring += inchar;                                          //add it to the inputString
              if(inchar == '\r') {sensor_stringcomplete = true;}               //if the incoming character is a <CR>, set the flag 
             }

float getTemperature(){
  //Return Temperature in Celsius
  SHT_sendCommand(B00000011, SHT_dataPin, SHT_clockPin);
  SHT_waitForResult(SHT_dataPin);

  int val = SHT_getData(SHT_dataPin, SHT_clockPin);
  SHT_skipCrc(SHT_dataPin, SHT_clockPin);
  return (float)val * 0.01 - 40; //convert to celsius
}

float getHumidity(){
  //Return  Relative Humidity
  SHT_sendCommand(B00000101, SHT_dataPin, SHT_clockPin);
  SHT_waitForResult(SHT_dataPin);
  int val = SHT_getData(SHT_dataPin, SHT_clockPin);
  SHT_skipCrc(SHT_dataPin, SHT_clockPin);
  return -4.0 + 0.0405 * val + -0.0000028 * val * val; 
}


void SHT_sendCommand(int command, int dataPin, int clockPin){
  // send a command to the SHTx sensor
  // transmission start
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  digitalWrite(dataPin, HIGH);
  digitalWrite(clockPin, HIGH);
  digitalWrite(dataPin, LOW);
  digitalWrite(clockPin, LOW);
  digitalWrite(clockPin, HIGH);
  digitalWrite(dataPin, HIGH);
  digitalWrite(clockPin, LOW);

  // shift out the command (the 3 MSB are address and must be 000, the last 5 bits are the command)
  shiftOut(dataPin, clockPin, MSBFIRST, command);

  // verify we get the right ACK
  digitalWrite(clockPin, HIGH);
  pinMode(dataPin, INPUT);

  if (digitalRead(dataPin)) Serial.println("ACK error 0");
  digitalWrite(clockPin, LOW);
  if (!digitalRead(dataPin)) Serial.println("ACK error 1");
}


void SHT_waitForResult(int dataPin){
  // wait for the SHTx answer
  pinMode(dataPin, INPUT);

  int ack; //acknowledgement

  //need to wait up to 2 seconds for the value
  for (int i = 0; i < 1000; ++i){
    delay(2);
    ack = digitalRead(dataPin);
    if (ack == LOW) break;
  }

  if (ack == HIGH) Serial.println("ACK error 2");
}

int SHT_getData(int dataPin, int clockPin){
  // get data from the SHTx sensor

  // get the MSB (most significant bits)
  pinMode(dataPin, INPUT);
  pinMode(clockPin, OUTPUT);
  byte MSB = shiftIn(dataPin, clockPin, MSBFIRST);

  // send the required ACK
  pinMode(dataPin, OUTPUT);
  digitalWrite(dataPin, HIGH);
  digitalWrite(dataPin, LOW);
  digitalWrite(clockPin, HIGH);
  digitalWrite(clockPin, LOW);

  // get the LSB (less significant bits)
  pinMode(dataPin, INPUT);
  byte LSB = shiftIn(dataPin, clockPin, MSBFIRST);
  return ((MSB << 8) | LSB); //combine bits
}

void SHT_skipCrc(int dataPin, int clockPin){
  // skip CRC data from the SHTx sensor
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  digitalWrite(dataPin, HIGH);
  digitalWrite(clockPin, HIGH);
  digitalWrite(clockPin, LOW);
}


void printDate(){

  
 
  
   float temperature = getTemperature();
   float humidity = getHumidity();

   
  
     if (Serial2.available() > 0) {
   float inChar = Serial2.parseFloat();
  Serial.print("PH = ");
  Serial.print(inChar);
   Serial.println("");
   
  Serial.print("temperature = ");  
  Serial.print(temperature);
  Serial.println("");
  

     }
}